On Mon, Mar 07, 2016 at 04:10:47PM +0100, Jan Glauber wrote:
> From: David Daney <david.daney@cavium.com>
> 
> If I2C_M_RECV_LEN is set consider the length byte.
> 
> Signed-off-by: David Daney <ddaney@caviumnetworks.com>
> Signed-off-by: Jan Glauber <jglauber@cavium.com>

You also might want to set "| I2C_FUNC_SMBUS_READ_BLOCK_DATA |
I2C_FUNC_SMBUS_BLOCK_PROC_CALL" in your functionality?

> +		if (recv_len && i == 0) {
> +			if (data[i] > I2C_SMBUS_BLOCK_MAX + 1) {
> +				dev_err(i2c->dev,
> +					"%s: read len > I2C_SMBUS_BLOCK_MAX %d\n",
> +					__func__, data[i]);
> +				return -EIO;

According to Documentation/i2c/fault-codes this should be -EPROTO.